tbuckley/cabot-search huggingface dataset:
Abstract A040: In vivo imaging of ovarian and non-small cell lung cancer models hosted in the Sprague-Dawley Rag2 null Il2rgamma null SRG rat (OncoRat®)
Authors: Diane Begemann, Nicolas Johnston, Marissa O’Callaghan, Grace Walton, Valeriya Steffey, Fallon Noto
Journal: Cancer Research (2023)

Abstract Human cancer xenografts are a vital tool for understanding tumor biology. While in vivo studies are traditionally done in immunocompromised mice, we have created the SRG OncoRat® that is an excellent host for human xenografts. In vivo luminescent imaging is routinely used in mouse models, and it is particularly useful for studying orthotopic xenografts or metastatic models. In this study, we validated the SRG rat as a model that can effectively be used for in vivo imaging of human cancers. For the current study, we assessed two tumor models. OV81.2-luc is a luciferase positive cell line that was generated from ascites collection from a grade IIIC serous ovarian carcinoma. Tumors were established by inoculating OV81.2-luc cells IP into female SRG rats and female NSG mice, then treated with vehicle or cisplatin for 28 days. Human non-small cell lung cancer line H358-luc is luciferase positive and metastasizes to lung when injected subcutaneously into the hind flank of SRG rats. Tumors were measured thrice weekly with calipers. For both studies, we performed weekly in vivo luciferase imaging using Spectral Instruments AMI-HT. Tumors established rapidly for both OV81.2-luc and H358-luc in both SRG rats and NSG mice, with luciferin positive signal starting one week post inoculation. In OV81.2-luc hosting animals, upon necropsy, tumors were found on multiple abdominal organs including the peritoneum, ovary, mesentery, intestines, kidneys, liver, and body cavity wall. Metastatic events outside the abdominal cavity were not evident in OV81.2-luc hosting animals. In H358-luc tumor bearing rats, a high metastatic tumor burden was found in the lungs. These data confirm that the SRG rat is an excellent host for studying human cancer when compared to commonly used immunodeficient mouse models. Data demonstrate that the SRG rat has a high utility for studies using both in vivo imaging, such as orthotopic tumor implantation, and studies on metastasis. As the most immunodeficient rat commercially available, the SRG rat retains the ability to establish human tumors while possessing size, physiology, and metabolism-based advantages when compared to mice. Citation Format: Diane Begemann, Nicolas Johnston, Marissa O’Callaghan, Grace Walton, Valeriya Steffey, Fallon Noto. In vivo imaging of ovarian and non-small cell lung cancer models hosted in the Sprague-Dawley Rag2 null Il2rgamma null SRG rat (OncoRat®) [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A040.
Abstract B050: Reproducible and effective preclinical models of prostate cancer metastasis established with PDXs
Authors: JuanJuan I. Yin, Asha Daryanani, Aian Alilin, Ross Lake, Kathy Kelly
Journal: Cancer Research (2023)

Abstract Metastatic castration resistant prostate cancer (mCRPC) is a lethal disease. Understanding the intricacy of this disease and developing targeted treatment is hampered by the lacking of clinically relevant animal models. LuCaP patient-derived xenografts (PDXs), established from advanced metastatic prostate cancer, are a large cohort that encompass the molecular and cellular heterogeneity of mCRPC. We have established four prostate cancer metastasis models from three androgen receptor (AR) positive lines (LuCaP136, LuCaP167 and LuCaP23.1) and one AR negative line LuCap145.2. The three AR positive LuCap lines metastasized to vertebrae and long bones with differing bone-associated histology while the AR negative LuCap145.2 metastasize to brain and spinal cord. The bone metastasis phenotypes of the models encompass: osteolytic (LuCaP136), mixed bone destruction and new bone formation (LuCaP167), and a highly osteoblastic histology (LuCaP23.1). LuCap136 and LuCap167 also metasize to soft tissues including adrenal, kidney and liver. Castration responses were studied on LuCap136 and LuCap167 models. Although both models are castration resistant, LuCap136 model initially are sensitive to castration with decreased tumor progression, and AR down-regulated in the metastatic sites. In contrast, tumor progression was not affected after castration in LuCap167 model. AR and ARV7 were up-regulated in metastatic cells. In summary, the LuCap PDX lines have the capacity for systemic growth in clinically accurate metastatic sites. In addition, the two AR positive models show different castration response which may be driven by different pathways. Understanding the complexity of these pathways would guide optimal selection of drug combinations to achieve the best outcome for patients with mCRPC. Citation Format: JuanJuan I. Yin, Asha Daryanani, Aian Alilin, Ross Lake, Kathy Kelly. Reproducible and effective preclinical models of prostate cancer metastasis established with PDXs [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B050.
Abstract A005: Adherent-to-suspension transition by hematopoietic factors promotes metastatic dissemination
Authors: Hyunbin D. Huh, Heon Yung Gee, Hyun Woo Park
Journal: Cancer Research (2023)

Abstract How primary tumor cells reprogram their anchorage dependency to disseminate into the bloodstream remain elusive. Here, we discover a biological phenomenon referred to as “Adherent-to-Suspension Transition” (AST) that reprograms adherent cells into suspension cells by introducing four hematopoietic transcriptional regulators, which we designated AST factors. Induction of AST factors in adherent cells suppress Hippo transducers YAP-TEAD and upregulate globin genes that evoke spontaneous cell-matrix dissociation and anoikis resistance in the absence of lineage differentiation. During dissemination, we uncover the aberrant induction of AST factors in circulating tumor cells (CTCs) derived from de novo metastatic breast cancer patients and mouse models in vivo. Pharmacological blockade of AST factors in breast cancer cells abrogates CTC formation and suppresses lung metastases without affecting the primary tumor growth. Collectively, we demonstrate that suspension cells can directly arise from adherent cells by the addition of defined factors that confer metastatic traits. Furthermore, our data expand the prevailing cancer treatment paradigm toward direct intervention within the metastatic spread of cancer. Citation Format: Hyunbin D. Huh, Heon Yung Gee, Hyun Woo Park. Adherent-to-suspension transition by hematopoietic factors promotes metastatic dissemination [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A005.
Abstract PR010: Multiplex imaging reveals features of organotropism in pancreatic ductal adenocarcinoma
Authors: Jennifer Eng, Jason Link, Carl Pelz, Rosalie Sears
Journal: Cancer Research (2023)

Abstract PDAC patients have a dismal prognosis with an 11% 5-year survival rate, driven in part by the fact that 90% of patients are diagnosed with metastatic disease. In a cohort of 300 PDAC patients, we observed that patients who had lung-only metastasis had longer overall survival than the majority of patients with metastasis to the liver. We used gene expression data to develop a signature based on gene expression in primary tumors of liver versus lung organotropism, which we called pORG. Our pORG signature predicts long term survival in PDAC patients and reveals unique features of the primary tumor, including increased interferon and immune activity in lung tropic tumors and increased proliferation and replication stress in liver-tropic tumors. To validate our findings, we generated cyclic immunofluorescence multiplex imaging data for a subset of 34 patients. Single cell image analysis revealed B and T cell infiltration and spatial clustering in low pORG/ lung tropic tumors, and markers of replication stress in high pORG patients. Our work suggests unique targetable tumor and microenvironment features linked to organotropism in PDAC. Citation Format: Jennifer Eng, Jason Link, Carl Pelz, Rosalie Sears. Multiplex imaging reveals features of organotropism in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr PR010.
Abstract A013: Loss of MLL3 epigenetic regulator drives metastasis by promoting a hybrid epithelial-mesenchymal transition state
Authors: Jihong Cui, Chi Zhang, Ji-Eun Lee, Boris Bartholdy, Dapeng Yang, Yu Liu, Piril Erler, Phillip Galbo, Dayle Q. Hodge, Danwei Huangfu, Deyou Zheng, Kai Ge, Wenjun Guo
Journal: Cancer Research (2023)

Abstract Phenotypic plasticity associated with the hybrid epithelial-mesenchymal transition (EMT) state is crucial to metastatic seeding and outgrowth. However, the mechanisms controlling the induction of hybrid EMT remain poorly defined. We showed that deletion of the epigenetic regulator MLL3, a tumor suppressor frequently altered in human cancer, promoted the acquisition of the hybrid EMT state in both epithelial and mesenchymal breast cancer cells by facilitating EMT and mesenchymal-epithelial transition, respectively, distinct from other known EMT regulators mediating unidirectional changes. Consequently, MLL3 deletion greatly increased metastasis by enhancing metastatic colonization. MLL3 loss led to increased IFNg signaling, which is required for the induction of hybrid EMT cells and the enhanced metastatic capacity. Mechanically, MLL3 loss enhanced IFNg signaling by increasing H3K27ac intensity in the enhancers of a subset of IFNg response genes in both epithelial and mesenchymal tumor cells. We further showed that MLL3-deficient cells were sensitive to BET inhibition, which effectively suppressed the growth of MLL3-mutant primary tumors and metastases. These results uncovered a key driver of the hybrid EMT state in breast cancer that could be targeted therapeutically. Citation Format: Jihong Cui, Chi Zhang, Ji-Eun Lee, Boris Bartholdy, Dapeng Yang, Yu Liu, Piril Erler, Phillip Galbo, Dayle Q. Hodge, Danwei Huangfu, Deyou Zheng, Kai Ge, Wenjun Guo. Loss of MLL3 epigenetic regulator drives metastasis by promoting a hybrid epithelial-mesenchymal transition state [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A013.
Abstract A023: OGT/CDK5/ACSS2 axis regulates breast cancer brain metastatic growth
Authors: Emily Esquea, Lorela Ciraku, Giang Le Minh, Mauricio Reginato
Journal: Cancer Research (2023)

Abstract Brain metastases (BMs) in breast cancer patients is considered an end-stage event, with no effective drug treatment and a median survival after diagnosis measured in months. Currently, there are no effective drug treatment for BM patients, thus there is an urgent need to develop novel treatment strategies. Breast cancers that metastasize to the brain must adapt to lack of lipid availability in the brain environment and are highly dependent on fatty acid synthesis for growth and survival. However, the signaling pathways that regulate precursors of fatty acid synthesis and lipid metabolism in breast cancer brain metastatic (BCBM) tumors are not known. Here, we show that BCBM cells can generate acetyl-CoA, a major metabolite feeding lipid biosynthesis, via phosphorylation of acetyl-CoA synthetase 2 (ACSS2) by the cyclin-dependent kinse-5 (CDK5) regulated by the nutrient sensor O-GlcNAc transferase (OGT). Breast cancer cells selected to metastasize to the brain contain higher levels of O-GlcNAcylation, OGT. and ACSS2-Ser267 phosphorylation compared to parental cells, and we show that human breast cancer brain metastatic patient samples contain elevated ACSS2-Ser-267 levels. Additionally, overexpression of the OGT, CDK5, or ACSS2-S267D phospho-mimetic mutant confers a growth advantage of breast cancer cells in the brain in vivo. Importantly, we show that ACSS2 is required for breast cancer growth in the brain but not in the mammary fat pad. Transcriptome analysis shows that ACSS2 regulates E2F-regulated genes and E2F1 protein levels in breast cancer cells. Pharmacologically targeting the CDK5 or ACSS2 with respective small molecule inhibitors reduces tumor growth in orthotopic ex vivo brain slice model. These results suggest a crucial role for OGT/CDK5/ACSS2 signaling axis to regulate lipid metabolism in BCBM cells and identify CDK5 and ACSS2 as novel therapeutic targets for treatment of breast cancer brain metastatic growth. Citation Format: Emily Esquea, Lorela Ciraku, Giang Le Minh, Mauricio Reginato. OGT/CDK5/ACSS2 axis regulates breast cancer brain metastatic growth [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A023.
Abstract A022: Role of imaging mass cytometry in studying hepatoblastoma vascular invasion
Authors: Andres F. Espinoza, Roma Patel, Sarah Woodfield, Sanjeev A. Vasudevan
Journal: Cancer Research (2023)

Abstract Introduction: Hepatoblastoma (HB) is the most common liver cancer in children with a survival rate of less than 50% in patients with high-risk disease, especially those with vascular invasion (VI). Patients with VI receive aggressive therapies that are toxic and ineffective; therefore, a better understanding of the biomarkers and biology of VI in HB is urgently needed. Methods: Using imaging mass cytometry (IMC) we analyzed 18 pre-validated protein targets on two of our formalin-fixed paraffin embedded (FFPE) HB patient samples; one with VI and one without VI. For confirmation of the proteins of interest, we performed immunohistochemistry (IHC) on primary and metastatic lesions from a separate patient. We performed RNA sequencing of one of our primary liver tumor and two sub-clones of that tumor, one inside an intrahepatic vessel and one sample representing tumor vessel thrombus. Results: By IMC, we found that protein expression of c-Myc and YAP-1 are increased in the areas of VI as the tumor invades the neighboring blood vessel. YAP-1 and c-Myc expression were low in the patient without VI. When examining the IHC of the separate patient with metastatic lung disease, we noted clear nuclear positivity of YAP-1 and c-Myc in the metastatic cells, compared to the negative nature of the primary liver tumor. Our RNA sequencing data showed that the average gene expression of c-Myc of the tumor in intrahepatic vessel and tumor vessel thrombus was 1.61 times higher than the primary tumor. The tumor found in the intrahepatic vessel and tumor vessel was found to have 1.29 times higher expression of Yap-1 compared to the primary tumor. Conclusions: YAP-1 and c-Myc had higher expression in hepatoblastoma as the tumor cells progress to invade the vasculature and metastasize. YAP-1 and c-Myc expression appears to play a role in vascular invasion that is maintained when tumors grow in the metastatic sites. Citation Format: Andres F. Espinoza, Roma Patel, Sarah Woodfield, Sanjeev A. Vasudevan. Role of imaging mass cytometry in studying hepatoblastoma vascular invasion [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A022.
Abstract A042: Differences in gain-of-function and inhibitory effects amongst p53 mutants <i>in vivo</i>
Authors: Shunbin Xiong, Dhruv Chachad, Yun Zhang, Jovanka Gencel-Augusto, Mario Sirito, Vinod Pant, Peirong Yang, Chang Sun, Guillermina Lozano
Journal: Cancer Research (2023)

Abstract The majority of p53 missense mutations identified in cancer patients are in the DNA-binding domain and are characterized as either structural or contact mutations. These missense mutations exhibit inhibitory effects on wild-type p53 activity. More importantly, these mutations also demonstrate gain-of-function (GOF) activities characterized by increased metastasis, poor prognosis, and drug resistance. To better understand the activities by which TP53 mutations, identified in Li-Fraumeni syndrome, contribute to tumorigenesis in vivo, we generated a novel germline p53R245W allele (contact mutation) and compared it to existing p53R172H (structural mutation) and p53R270H (contact mutation) alleles. Thymocytes from heterozygous mice showed all three hot-spot mutations exhibited similar inhibitory effects on wild type p53 transcription in vivo and tumors from these mice had similar levels of loss of heterozygosity. However, the overall survival of p53R245W/+ and p53R270H/+ mice, but not p53R172H/+ mice, was significantly shorter than that of p53+/- mice, demonstrating p53 mutation-specific GOF contributions to tumor development. Furthermore, p53R245W/+ and p53R270H/+ mice had more osteosarcoma metastases than p53R172H/+ mice, indicating that these two contact mutants have stronger GOF in driving osteosarcoma metastasis. Omics analyses using RNA-sequencing data from p53R172H/+, p53R245W/+, and p53R270H/+ primary osteosarcomas in comparison to p53+/- indicated GOF was mediated by distinct pathways among the three mutations. Thus, both the inhibitory effect of mutant over WT p53, and GOF activities of mutant p53 contributed to tumorigenesis in vivo. Targeting p53 mutant-specific pathways may be important for therapeutic outcomes in osteosarcomas. Citation Format: Shunbin Xiong, Dhruv Chachad, Yun Zhang, Jovanka Gencel-Augusto, Mario Sirito, Vinod Pant, Peirong Yang, Chang Sun, Guillermina Lozano. Differences in gain-of-function and inhibitory effects amongst p53 mutants in vivo [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A042.
Abstract A018: Phosphorylated nuclear DICER1 promotes open chromatin state and lineage plasticity of lung adenocarcinomas
Authors: Raisa A. Reyes-Castro, Shin-Yu Chen, Jacob Seemann, Swathi Arur
Journal: Cancer Research (2023)

Abstract DICER1 controls micro(mi)RNA-mediated epithelial-to-mesenchymal transition (EMT) to regulate tumorigenesis of lung adenocarcinomas (LUADs). We discovered that DICER1 is phosphorylated by ERK and nuclear translocated and phospho-DICER1 contributes to tumorigenesis. Mechanisms through which phospho-DICER1 regulates tumor progression remain undefined. We show that phospho-nuclear DICER1 associates with invasive human LUADs with oncogenic KRAS mutations and promotes late-stage tumor progression in mice with oncogenic Kras mutations. Surprisingly, phosphomimetic DICER1 regulates LUAD progression independent of miRNAs and EMT. Integrating single-cell RNA sequencing, fluorescent in situ RNA hybridization, immunofluorescence, and ATAC-sequencing, in mice,we discovered that phosphomimetic DICER1 generates an open chromatin state in the lung tumor alveolar cells leading to expression of gastrointestinal genes and altered AT2 cell identity. Strikingly, we also observe the gastric gene signature in human LUADs with phospho-DICER1 and KRAS mutations. We propose that phosphorylated nuclear DICER1 regulates chromatin remodeling leading to tumor cell reprogramming which drives lung cancer progression. Citation Format: Raisa A. Reyes-Castro, Shin-Yu Chen, Jacob Seemann, Swathi Arur. Phosphorylated nuclear DICER1 promotes open chromatin state and lineage plasticity of lung adenocarcinomas [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A018.
Abstract A043: A novel role for Mitochondrial Rho GTPase 2 in tumor cell invasion and metastasis
Authors: Dillon P. Boulton, Madison Furnish, M. Cecilia Caino
Journal: Cancer Research (2023)

Abstract Metastasis of cancer cells to secondary sites remains the leading cause of cancer related deaths, emphasizing a strong need for actionable targets in advanced stage cancer. To address this, we study novel dysregulated signaling mechanisms that cells utilize to metastasize to distal sites. Here, we focus on how outer mitochondrial membrane protein—Mitochondrial Rho GTPase 2 (MIRO2)—promotes tumor cell invasion and metastasis through a negative regulation of RhoA. Our previous work identified higher MIRO2 mRNA expression in cancer vs. normal patient samples, which correlated with worse patient outcomes. Furthermore, in the context of prostate cancer we demonstrated that MIRO2 was critical for 2D cell growth, anchorage-dependent and -independent colony formation, and tumor growth in vivo. However, it remains completely unknown if MIRO2 affects primary tumor growth or if this protein is important throughout tumor progression. Using siRNA mediated knockdown (KD) of MIRO2 we clearly show that MIRO2 KD ubiquitously reduces tumor cell invasion in breast, melanoma, pancreatic, and prostate cancer cell lines. Preliminary experiments modeling late-stage metastasis showed that tail vein injection of PC3 cells stably expressing MIRO2 targeting shRNA had reduced kidney and liver metastatic burden in comparison to PC3 cells with control shRNA. In further mechanistic studies, we identified novel MIRO2 binding partners and used siRNA to KD the top hits and observe changes in invasive capacity. We found that atypical myosin IX B (MYO9B) reduced the invasion of cells to the largest extent. MYO9B is a plus-end direct atypical myosin known to control cell motility through spatially inactivating RhoA at the leading edge of migrating cells. Excitingly, MIRO2 KD showed an increase in active RhoA phenocopying MYO9B KD. Lastly, in pilot experiments we found that dual KD of MIRO2 and RhoA rescued invasive capacity in comparison to MIRO2 KD alone. Taken together, we propose a novel signaling mechanism by which MIRO2 broadly promotes invasion and metastasis through MYO9B dependent inactivation of RhoA. Citation Format: Dillon P. Boulton, Madison Furnish, M. Cecilia Caino. A novel role for Mitochondrial Rho GTPase 2 in tumor cell invasion and metastasis [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A043.